Condensation
Condensation and moisture on windows have become some of the most common complaints from today's homeowners.
Fortunately, the homeowner can control most condensation problems. The key to controlling excess condensation lies in understanding today's building standards and how relative humidity impacts on today's airtight homes. Listed below is a chart indicating desired maximum relative humidity for different temperatures.
Stained ceilings, water streaming from windows, and mold on walls and windowsills are often indications of excessive vapour in the air.
Condensation problems arise because air can only hold a limited amount of water vapour, an amount which varies with temperature. For example, cold air is able to hold less water vapour than warm air.
Air cooled by contact with cooler surfaces such as windows will therefore deposit water vapour on the glass or the sash because as the air is cooled, it loses some of its ability to hold water vapour. This surface condensation can therefore be seen as an indication of excessive water vapour in the air. Because of this characteristic, windows are the most common areas where condensation is most visible. As condensation occurs on the inside window surface, it may be a warning signal to reduce the humidity in your home.
The first step in solving the condensation problems in your home is a willingness to reduce humidity levels. While some humidity is recognized as necessary for comfort and health, any increase in moisture levels must be monitored to alleviate excess condensation. When using humidifiers, the homeowner should check that the level of moisture being added to the air does not cause surface condensation problems.
Listed below are practical suggestions in controlling humidity and related surface condensation on your windows.
Make it a habit to use your bathroom fan when showering and your kitchen exhaust fan when cooking. This procedure will help remove moist air from your homes.
Refrain from the use of humidifiers unless the relative humidity levels are below the levels suggested in the chart on the following page.
Refrain from over watering household plants.
Leave the fan running on the heating/air conditioning unit during extremely cold weather to help the air circulate throughout the home. Avoid hanging wet clothing inside the home.
Ensure the clothes dryer is vented to the exterior and the exhaust fan is operating during the use of the dryer.
Free circulation of air is important. Keep drapes open as much as possible so the air can circulate freely over the windows. If necessary, you may want to open windows to reduce localized condensation.
Do not worry about the small amount of heat you will lose by providing enough ventilation in cold weather to control the humidity. It will cost a great deal less than the damage condensation can do to your windows, wall and woodwork. Remember that it is the homeowner's responsibility to use the ventilation system properly to protect the home from stale air and moisture damage.